JPH0963621A - Manufacture of fuel cell and apparatus therefor - Google Patents

Abstract

PROBLEM TO BE SOLVED: To prevent evaporation of water in a solid polymer electrolytic membrane and reliably join electrodes by joining electrodes to both sides of an open part of a solid polymer electrolytic membrane unitedly sandwiched and fixed between frames by pressing and heating. SOLUTION: After a solid polymer electrolytic membrane 12 is sandwiched between a first and a second resin sheets 24a, 24b, the resultant membrane is sandwiched between a first and a second frame bodies 18a, 18b. Positioning is so carried out as to position open parts 26a, 26b of the resin sheets at open parts 16a, 16b of the frame bodies and then the sheets and frame bodies are unitedly fixed by fixing means 20. Then, a carbon paper sheet 14a and a resin sheet 28a for separation for an electrode precoated with a catalyst are inserted in the open part 16a of the first frame 18a and a carbon paper sheet 14b and a resin sheet 28b for separation for an electrode are inserted in the open part 16b of the frame body 18b. Next, a lower die 38 and an upper die 40 are set closely each other and the carbon paper sheets 14a, 14b and the solid polymer electrolytic membrane are sandwiched through the resin sheets 28a, 28b between a lower die pressing part 42 and an upper die pressing part 44 and heating and pressing is carried out by a heat pressing means 22.

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a fuel cell manufacturing method and apparatus for bonding electrodes to both surfaces of a solid polymer electrolyte membrane.

[0002]

2. Description of the Related Art For example, a fuel cell has been developed in which a plurality of fuel cell structures each having an anode electrode and a cathode electrode opposed to each other with a solid polymer electrolyte membrane interposed therebetween are sandwiched by a separator and stacked. Are being put to practical use for various applications.

In this type of fuel cell, for example, hydrogen gas (fuel gas) generated by steam reforming of methanol is supplied to an anode electrode and oxidizing gas (air) is supplied to a cathode electrode. Thus, the hydrogen gas is ionized and flows through the solid polymer electrolyte membrane, whereby electric energy is obtained outside.

By the way, in the above-mentioned fuel cell, the solid polymer electrolyte membrane is sandwiched between two catalyst electrodes (gas diffusion electrodes), and the work is integrated by heating and pressurizing the membrane. . For example, in the conventional manufacturing apparatus shown in FIG. 6, the catalyst electrodes 4 are formed on both sides of the solid polymer electrolyte membrane 2.
After arranging a and 4b, the catalyst electrodes 4a and 4b are heated and pressed by the press dies 8a and 8b via the rubber sheets 6a and 6b.

In this case, in the above apparatus, water in the solid polymer electrolyte membrane 2 easily evaporates from the gap between the solid polymer electrolyte membrane 2 and the rubber sheets 6a and 6b during heating. It has been pointed out that this causes the solid polymer electrolyte membrane 2 to deteriorate.

Therefore, the manufacturing method disclosed in Japanese Patent Laid-Open No. 3-295171 is adopted. In this manufacturing method, as shown in FIG. 7, spacers 5a, 5 having openings 3a, 3b corresponding to catalyst electrodes 4a, 4b are formed.
b is prepared, and the spacers 5a and 5b are interposed between the solid polymer electrolyte membrane 2 and the rubber sheets 6a and 6b. Therefore, the catalyst electrode 4 is pressed through the press dies 8a and 8b.
When joining a and 4b to both sides of the solid polymer electrolyte membrane 2,
Evaporation of water from the solid polymer electrolyte membrane 2 can be reliably prevented by the spacers 5a and 5b.

[0007]

However, in the above-mentioned conventional method, the pressing force by the press dies 8a and 8b is dispersed to the spacers 5a and 5b in addition to the catalyst electrodes 4a and 4b. As a result, the pressing force applied to the catalyst electrodes 4a, 4b decreases, and there is a problem that poor fusion between the catalyst electrodes 4a, 4b and the solid polymer electrolyte membrane 2 is caused. At that time, an attempt is made to increase the pressurizing time to avoid defective fusion between the catalyst electrodes 4a and 4b and the solid polymer electrolyte membrane 2, but this makes the cycle time longer and It has been pointed out that there is a problem of quality deterioration.

The present invention solves this kind of problem, and prevents evaporation of water from the solid polymer electrolyte membrane and ensures that electrodes are securely bonded to both surfaces of the solid polymer electrolyte membrane. It is an object of the present invention to provide a possible fuel cell manufacturing method and apparatus.

[0009]

In order to achieve the above-mentioned object, the present invention is such that a solid polymer electrolyte membrane is sandwiched between first and second frames, and the first and second frames are provided. With the electrode inserted in the formed opening, heating and pressure treatment are performed only from the opening to bond the electrodes to both surfaces of the solid polymer electrolyte membrane. in this way,
Since the solid polymer electrolyte membrane is sandwiched between the first and second frames, it is possible to prevent water from evaporating from the solid polymer electrolyte membrane during the heat treatment.

Moreover, since the heating and pressurizing treatment is applied to the electrode only through the opening, the pressing force is not dispersed to the electrodes other than this electrode, and the desired pressing force is surely applied to the electrode. It will be possible. Furthermore, by inserting the electrodes into the openings of the first and second frames, the electrodes can be accurately positioned with respect to the solid polymer electrolyte membrane.

Further, since the first and second resin sheets are interposed between the solid polymer electrolyte membrane and the first and second frames, the first and second frames are made of a metal material. At this time, it is possible to prevent metal ions from entering the solid polymer electrolyte membrane. Furthermore, by providing the releasing resin sheet having the same shape as the electrode, the electrode after heating and pressurizing can be smoothly separated from the hot pressing means.

[0012]

1 is an exploded perspective view of a fuel cell manufacturing apparatus 10 according to this embodiment. This manufacturing device 1
0 is for bonding the carbon paper (electrodes) 14a, 14b to which the catalyst has been applied in advance on both surfaces of the solid polymer electrolyte membrane 12, and corresponds to the size of the carbon papers 14a, 14b in the substantially central portion. Openings 16a, 1
First and second frame bodies 18a and 18b in which 6b is formed
And a fixing means 20 for integrally fixing the first and second frames 18a, 18b with the solid polymer electrolyte membrane 12 being sandwiched, and the carbon papers 14a, 14b in the openings 16a, 16b. The carbon paper 14 is inserted only through the openings 16a and 16b in the inserted state.
The heating and pressurizing means 22 for heating and pressurizing the a and 14b to bond the carbon papers 14a and 14b to both surfaces of the solid polymer electrolyte membrane 12.

Solid polymer electrolyte membrane 12 and first and second
First and second resin sheets 24a and 24b made of PTFE (polytetrafluoroethylene) or the like are interposed between the frame bodies 18a and 18b, and the first and second resin sheets 24a and 24b are also provided. The opening 2 corresponding to the dimensions of the carbon papers 14a and 14b is provided substantially at the center of
6a and 26b are formed. First and second frame 18
Molding resin sheets 28a, 28b made of a resin material such as PTFE having the same shape as the carbon papers 14a, 14b with the carbon papers 14a, 14b inside are inserted into the openings 16a, 16b of the a, 18b. To be done.

The solid polymer electrolyte membrane 12 has four corners cut out. Screw holes 30 are formed in the vicinity of the four corners of the first frame body 18a, respectively, while a plurality of hole portions 32 coaxial with the screw holes 30 are formed in the vicinity of the four corners of the second frame body 18b. In the vicinity of the four corners of the first and second resin sheets 24a, 24b, similarly, a plurality of hole portions 34a, 34b corresponding to the screw holes 30 are formed.

The fixing means 20 is provided with four setscrews 36, and the setscrews 36 form the holes 32 of the second frame 18b and the holes 34a of the first and second resin sheets 24a, 24b.
34b, and its tip is screwed into the screw hole 30 of the first frame 18a. As a result, the solid polymer electrolyte membrane 12 is integrally clamped and fixed between the first frame body 18a and the second frame body 18b via the first and second resin sheets 24a, 24b (FIGS. 2 and 5). 3).

The heating press means 22 comprises a lower mold 38 and an upper mold 4.
The lower die 38 and the upper die 40 are provided with heating means such as a heater (not shown). Lower mold 3
A lower die press portion 42 and an upper die press portion 44 are formed on the upper die 8 and the upper die 40 so as to face each other. As shown in FIG. 4, the carbon papers 14 a and 14 b are attached to the solid polymer electrolyte membrane 1 through the lower mold pressing part 42 and the upper mold pressing part 44.
When the pressure is increased to 2, a predetermined gap H is formed between the second frame 18b and the upper mold 40.

More specifically, as shown in FIG. 5, the height A1 of the lower die press portion 42 and the thickness B1 of the release sheet 28a.
And the thickness C1 of the carbon paper 14a is the thickness A2 of the first frame 18a and the thickness B2 of the first resin sheet 24a.
Is equal to the sum of (A1 + B1 + C1 = A2 + B2). On the other hand, the height A3 of the upper die press portion 44 and the release resin sheet 2
The sum of the thickness B3 of 8b and the thickness C3 of the carbon paper 14b is the thickness A4 of the second frame 18b and the second resin sheet 2.
It becomes larger than the sum of 4b and thickness B4 (A3 + B3 + C
3> A4 + B4).

The operation of the manufacturing apparatus 10 thus configured will be described in connection with the manufacturing method according to this embodiment.

First, after the solid polymer electrolyte membrane 12 is sandwiched between the first and second resin sheets 24a and 24b,
The first and second resin sheets 24a and 24b and the solid polymer electrolyte membrane 12 are the first and second frame members 18.
It is sandwiched between a and 18b. Here, the first and second resin sheets 24a and 24b are positioned such that the openings 26a and 26b are located in the openings 16a and 16b of the first and second frame bodies 18a and 18b, respectively. The second frame bodies 18a and 18b are integrally fixed via the fixing means 20.

That is, each set screw 36 constituting the fixing means 20 is inserted into the hole 32 of the second frame 18b, the hole 34b of the second resin sheet 24b and the hole 34a of the first resin sheet 24a. Each tip is the first frame 18
It is screwed into the screw hole 30 of a. Thereby, the first and second frame bodies 18a and 18b, the first and second resin sheets 2 are formed.
4a, 24b and the solid polymer electrolyte membrane 12 are integrally fixed (see FIGS. 2 and 3).

Next, the carbon paper 14a coated with the catalyst in advance and the release resin sheet 28a are inserted into the opening 16a of the first frame 18a. On the other hand, the second frame 1
Similarly, a carbon paper 14b coated with a catalyst and a release resin sheet 28b are inserted into the opening 16b of 8b, and the solid polymer electrolyte membrane 12 is sandwiched between the carbon papers 14a and 14b.

Therefore, as shown in FIG. 4, the lower die 38 and the upper die 40 constituting the heating press means 22 are displaced in a direction in which they are close to each other, and the lower die press portion 42 and the upper die press portion 4 are moved.
4, the carbon papers 14a and 14b which are the electrode portions and the solid polymer electrolyte membrane 12 are the resin sheets 28a and 28 for releasing.
It is sandwiched by interposing b. Then, while being heated to 100 ° C. to 150 ° C. by a heating means (not shown), pressure treatment is performed.

In this case, in this embodiment, as shown in FIG. 4, the entire surface of the solid polymer electrolyte membrane 12 has the first and second surfaces.
It is sandwiched between the first and second frame bodies 18a and 18b via the resin sheets 24a and 24b. Therefore, when the heating and pressurizing process is performed by the heating press unit 22,
It is possible to prevent water from evaporating from the solid polymer electrolyte membrane 12.

Moreover, since the first and second resin sheets 24a and 24b are interposed between the solid polymer electrolyte membrane 12 and the first and second frame bodies 18a and 18b, the first and second frame bodies are provided. When 18a and 18b are made of a metal material, it becomes possible to prevent metal ions from entering the solid polymer electrolyte membrane 12. In addition, the first and second frames 18a and 18b are made of a resin-based material such as PT.
If it is made of FE, the first and second resin sheets 24 are formed.
It is not necessary to use a and 24b.

Further, a gap H is formed between the upper die 40 and the second frame 18b when the heat pressing means 22 pressurizes. As a result, the lower die pressing portion 42 and the upper die pressing portion 44 are provided with the opening 1 of the first and second frames 18a and 18b.
Carbon paper 14a, 14b from 6a, 16b only
Is not applied, and the pressing force (pressing force) is not dispersed on the first and second frame bodies 18a, 18b side. Therefore,
A desired pressing force can be surely applied to the carbon papers 14a and 14b.
It is possible to prevent defective fusion between the a and 14b and the solid polymer electrolyte membrane 12. This has the effect that a high-quality fuel cell can be obtained quickly and efficiently.

Furthermore, carbon papers 14a, 1
4b is the opening 1 of the first and second frame bodies 18a, 18b.
6a, 16b and first and second resin sheets 24a, 24
Positioned on both surfaces of the solid polymer electrolyte membrane 12 through the openings 26a and 26b of b. Therefore, there is an advantage that the relative positioning work of the carbon papers 14a and 14b and the solid polymer electrolyte membrane 12 can be performed with high accuracy and easily.

[0027]

In the method and apparatus for producing a fuel cell according to the present invention, the solid polymer electrolyte membrane is sandwiched between the first and second frames, so that water vapor is evaporated from the solid polymer electrolyte membrane during heat treatment. Can be prevented. Moreover, since the heating and pressurizing treatments are applied to the electrode only from the openings of the first and second frames, the pressing force is not dispersed to the electrodes other than this electrode, and the desired pressing force is applied to the electrode. Can be surely given. Further, the electrode is accurately positioned with respect to the solid polymer electrolyte membrane through the openings of the first and second frames.

Also, since the first and second resin sheets are interposed between the solid polymer electrolyte membrane and the first and second frames, the first and second frames are made of a metal material. At this time, it is possible to prevent metal ions from entering the solid polymer electrolyte membrane. Furthermore, by providing the releasing resin sheet having the same shape as the electrode, the electrode after heating and pressurizing can be smoothly separated from the hot pressing means.

[Brief description of drawings]

FIG. 1 is an exploded perspective view of a manufacturing apparatus according to the present invention.

FIG. 2 is a partially exploded perspective view of the manufacturing apparatus.

FIG. 3 is a vertical cross-sectional view of FIG.

FIG. 4 is a longitudinal sectional view of the manufacturing apparatus during operation.

5 is a partially enlarged explanatory view of FIG. 4. FIG.

FIG. 6 is an explanatory diagram of a manufacturing method according to a conventional technique.

FIG. 7 is an explanatory diagram of another manufacturing method according to the related art.

[Explanation of symbols]

10 ... Manufacturing apparatus 12 ... Solid polymer electrolyte membrane 14a, 14b ... Carbon paper 16a, 16b ...
Openings 18a, 18b ... Frame body 20 ... Fixing means 22 ... Heating press means 24a, 24b, 28a, 28b ... Resin sheet 36 ... Set screw 38 ... Lower mold 40 ... Upper mold 42 ... Lower mold press part 44 ... Upper mold press Department

Claims (4)

[Claims] 1. A method of manufacturing a fuel cell for bonding electrodes to both surfaces of a solid polymer electrolyte membrane, comprising first and second openings each having an opening corresponding to a size of the electrodes formed in a substantially central portion thereof. A step of sandwiching the solid polymer electrolyte membrane with a frame and fixing the first and second frames integrally; and inserting the electrodes into the openings of the first and second frames, respectively. And a step of sandwiching the solid polymer electrolyte membrane between the electrodes, and a step of heating and pressurizing the electrode only through the opening to bond the electrodes to both surfaces of the solid polymer electrolyte membrane. A method of manufacturing a fuel cell having the characteristics 2. A fuel cell manufacturing apparatus for bonding electrodes to both surfaces of a solid polymer electrolyte membrane, wherein first and second openings are formed in substantially the center portion corresponding to the dimensions of the electrodes. A frame body; fixing means for integrally fixing the first and second frame bodies in a state where the solid polymer electrolyte membrane is sandwiched; and the electrodes in respective openings of the first and second frame bodies. In a state where the solid polymer electrolyte membrane is sandwiched between the electrodes by inserting a heating press means for heating and pressurizing the electrode only from the opening and joining the electrodes to both surfaces of the solid polymer electrolyte membrane. An apparatus for manufacturing a fuel cell, comprising: 3. The manufacturing apparatus according to claim 1, further comprising first and second resin sheets interposed between the solid polymer electrolyte membrane and the first and second frame bodies, and the first and second resin sheets. An apparatus for manufacturing a fuel cell, characterized in that an opening corresponding to the size of the electrode is formed substantially in the center of the second resin sheet. 4. A mold releasing resin according to claim 1 or 2, wherein the electrodes are inserted into the respective openings of the first and second frames with the electrodes inside, and the mold releasing resin has the same shape as the electrodes. An apparatus for manufacturing a fuel cell, comprising a sheet.